The field of writing tools and implements has grown to the extent that there now are writing and marking tools and implements for numerous individual and stylized uses. Thus, ballpoint pens with replaceable tips and cartridges, and in a variety of ink colors, are common in homes and offices. The replaceable tips also provide the user with various style of line width from fine point to broad point. The writing tips can be retractable or non-retractable and either ballpoint or roller ball.
Felt tip pens intended for artwork and marker and highlighting are also common, and now come in colors that range across the spectrum; the writing tips are generally larger and wider than the ink pen tips in order to make the distinctive and easily discernible color highlighting or marking lines on, for example, books, posters, signs and artwork. The ink for the marking pens can be permanent, dry erase or wet erase. In addition, marker pens now come in liquid ink in a range of fluorescent colors.
Another type of specialized writing implement is the mechanical pencil used by draftsmen, architects, illustrators, surveyors, etc., that employs a simple twisting or pushing action on the body, or a portion of the pencil body, to advance and retract the lead. Many types of mechanical pencils include refillable cartridges that are stacked and stored within the pencil body. Moreover, the bodies of the above-described writing tools can include rubber grips for enhancing the writing comfort of the user.
One of the most common uses for writing tools and implements is in assisting the individual in solving alphanumeric puzzles that can include crossword puzzles, anagrams, rebuses, word scrambles and word searches wherein the writing tool is used to cross off or encircle the letters and words of the particular puzzle as they are disclosed or uncovered. However, depending on the type of writing tool used, crossing out the letters or words can completely obscure them causing the individual to lose track of which letters and words have been used or discovered. In addition, crossing off or blotting out the letters and words tends to clutter up the puzzle making it more difficult to discern correct letter and word combinations.
Thus, the prior art discloses a variety of writing tools and implements that incorporate pen, pencil or felt tip marker nibs for both fine and broad line writing, marking and highlighting, and also specially designed ends for marking and scoring certain types of printed surfaces.
For example, the Carlson patent (PCT patent WO 91/00810) discloses a dual tip marking and writing implement that includes a fine line-marking nib coaxially disposed within the nib aperture of a marking nib. The fine line-writing nib is retractable within the nib aperture so that the implement can be used as a conventional highlighting marker, and when the fine line-marking nib is projected past the nib aperture, the implement functions as a traditional protract-retract ink pen.
The Panopoulos patent (U.S. Pat. No. 5,067,837) discloses a variable point writing instrument wherein the writing tip is selectively expandable between a smallest diametric dimension and a largest diametric dimension.
The Coon patent (U.S. Pat. No. 6,213,661 B1) discloses a retractable felt-tipped pen and includes a flexible membrane disposed between movable cylindrical members one of which has a pen nib connected thereto. The flexible membrane is rotatable for sealing and exposing the pen nib as desired by the user.
The Holbrook et al. patent (U.S. Pat. No. 6,155,733) discloses an adjustable multi-tip marker for producing distinctive outlining or highlighting effects, and includes at least a pair of slidable, retractable tips disposed beside a fixed tip with all the tips being encased within the hollow body of the writing implement.
The Lychwick patent (U.S. Pat. No. 6,481,908 B2) discloses a multi-function marking pencil that has the ability to fill in score spaces on standardized tests, such as scholastic aptitude tests, and to remove the cover layer from cards, such as lottery cards.
Nonetheless, despite the ingenuity of the above devices, there remains the need for a writing implement that can provide both pen and pencil writing functions in combination with a circular marking function for marking printed surfaces representing various types of alphanumeric puzzles and word games as part of their solution.